When I heard they were doing a sequel to the 1st clip show episode I really didn't think much over but WOW was this a good follow up. And like Paradigms of Human Memory I wish that they did make full episodes from some of the clips that they showed (like the film noir paintball or an episode with the wig party). You also get to see more weird classes that you can take at Greendale. But by far this episode is totally worth seeing just for one scene alone, where we see the "truth" behind the study groups Greendale experience. That scene with the Greendale 7 + Leonard in the Asylum was well worth the watch and if the series ended on that note it would have weirdly made sooo much sense. But it was a fun way to call back to previous episodes.
Is it worth skipping? well my answer would be: who would skip a Community episode?
but i guess if you didnt like their first clip show episode you might not like this one. But if you like Community you'll most likily like this episode too